Strangely enough I've used pretty much every single product you mention. I might rebut: 1. GH/RB vs Bemani: Guitar Freaks only had 3 buttons versus 5 in Guitar

Strangely enough I've used pretty much every single product you mention. I might rebut: 1. GH/RB vs Bemani: Guitar Freaks only had 3 buttons versus 5 in Guitar Hero. Also the home versions of BM/GF/DM/DDR were always poor copies of the arcade versions - missing songs, badly-made input devices. And having western music is a big feature. 2. Game Gear: Personally I switched to Game Boy because of by crappy battery life, huge un-carryable size, bad build quality (it broke a couple of times). Wiki mentions lack of UK/US developer engagement meaning not many local games. 3. Apple: Stable, UNIX-based computers, which are also good for graphics and office use? iPad? iPods? Multi-touch, touch-sensitive scroll wheels, playlists, iTunes Store (100% legal, cheap, good selection of music, which feeds straight to the iPod)... In each case users did lose some features. But they gain some as well - I don't think any are really subsets of the alternatives. I switched to some of these specifically for better features. Personally I think usability is nice but it's a secondary differentiator after providing the best features for the largest market segment your product can target. There are some really ugly products out there which survive by virtue of just being the most useful. That said, successful products also tend to usually also be highly usable because the consumer market is the biggest segment (contrast - enterprise software). Or in cases where usability is the feature - accessibility software? GUI?